Abordagem de modelos lineares generalizados mistos para analisar nodulação em linhagens de feijoeiro-comum

The objective of this work was to compare distributions for the modeling of the number and dry matter weight of nodules (DWN) of Rhizobium from different inoculants in common bean (Phaseolus vulgaris) inbred lines subjected to nitrogen doses, as well as to identify the best inoculant for those lines. The experiment was carried out in a randomized complete block design, arranged in split-split plots, with three factors – four inbred lines, five nitrogen doses (0, 20, 40, 60, and 80 kg ha-1), and three inoculants (CIAT 899, UFLA 02-100, and peat) – and four replicates. The number of nodules and their dry matter weight were analyzed with the generalized linear mixed modeling approach. The highest number of nodules was obtained with the CIAT 899 inoculant, at the dose of 20 kg ha-1 N (260 nodules), followed by UFLA 02-100, at 80 kg ha-1 (109 nodules), and peat alone at 20 kg ha-1 (98 nodules). The DWN with CIAT 899 exceeded in 0.66 g the DWN with UFLA 02-100, and in 0.95 g the DWN obtained without inoculation (inoculated with peat alone). The use of the negative binomial distribution and of the gamma distribution is a simple way to control data overdispersion of the nodule number and data underdispersion of DWN, respectively.O objetivo deste trabalho foi comparar distribuições para a modelagem do número e da massa de matéria seca de nódulos (MSN) de Rhizobium de diferentes inoculantes em linhagens de feijoeiro-comum (Phaseolus vulgaris) submetidas a diferentes doses de nitrogênio, bem como identificar o melhor inoculante para essas linhagens. O experimento foi instalado em blocos completos ao acaso, arranjados em parcelas subsubdivididas, com três fatores – quatro linhagens, cinco doses de nitrogênio (0, 20, 40, 60 e 80 kg ha-1) e três inoculantes (CIAT 899, UFLA 02-100 e turfa) – e quatro repetições. O número de nódulos e sua massa de matéria seca foram avaliados com a abordagem de modelos lineares generalizados mistos. O maior número de nódulos foi obtido com o inoculante CIAT 899 à dose de 20 kg ha-1 de N (260 nódulos), seguido do UFLA 02-100 a 80 kg ha-1 (109 nódulos) e de turfa sozinha (98 nódulos) a 20 kg ha-1. A MSN com o inoculante CIAT 899 excedeu em 0,66 g a MSN com o UFLA 02-100, e em 0,95 g a MSN obtida sem inoculação (inoculação com turfa apenas). O uso das distribuições bionomial negativa e gama é uma maneira simples de controlar a superdispersão dos dados do número de nódulos e a subdispersão dos dados de MSN, respectivamente

<b>Analysis of the genetic diversity of <i>Eucalyptus cladocalyx</i> (sugar gum) using ISSR markers

Eucalyptus cladocalyx F. Muell is a tree endemic to southern Australia and is distributed across four isolated regions: Kangaroo Island, southern Flinders Ranges, and two geographical zones in Eyre Peninsula. E. cladocalyx is capable of growing under extreme environmental conditions, including dry and saline soils. The objective of this study was to analyze genetic diversity in 45 half-sib families planted in northern Chile that are distributed across five different zones (provenances). Genetic variability was assessed using ISSR (Inter Simple Sequence Repeat) molecular markers. The results showed low levels of genetic diversity within populations (He = 0.113 to 0.268) in contrast with other Eucalyptus species. In addition, there was a significant genetic differentiation among provenances (Φst = 0.14); populations from the Kangaroo Island provenance showed more differentiation than any other population. These results are in agreement with previous studies of the species. Our study revealed that Chilean resources are a representative sample of Australian populations; therefore, the germplasm planted in northern Chile would be sufficient for the development of improvement programs. ISSR-Marker technology could be an alternative to identify genotypes of interest in material selection

Climate and Land Cover Trends Affecting Freshwater Inputs to a Fjord in Northwestern Patagonia

International audienceFreshwater inputs strongly influence oceanographic conditions in coastal systems of northwestern Patagonia (41–45°S). Nevertheless, the influence of freshwater on these systems has weakened in recent decades due to a marked decrease in precipitation. Here we evaluate potential influences of climate and land cover trends on the Puelo River (640 m 3 s –1 ), the main source of freshwater input of the Reloncaví Fjord (41.5°S). Water quality was analyzed along the Puelo River basin (six sampling points) and at the discharge site in the Reloncaví Fjord (1, 8, and 25 m depth), through six field campaigns carried out under contrasting streamflow scenarios. We also used several indicators of hydrological alteration, and cross-wavelet transform and coherence analyses to evaluate the association between the Puelo River streamflow and precipitation (1950–2019). Lastly, using the WEAP hydrological model, land cover maps (2001–2016) and burned area reconstructions (1985–2019), we simulated future land cover impacts (2030) on the hydrological processes of the Puelo River. Total Nitrogen and total phosphorus, dissolved carbon, and dissolved iron concentrations measured in the river were 3–15 times lower than those in the fjord. Multivariate analyses showed that streamflow drives the carbon composition in the river. High streamflow conditions contribute with humic and colored materials, while low streamflow conditions corresponded to higher arrival of protein-like materials from the basin. The Puelo River streamflow showed significant trends in magnitude (lower streamflow in summer and autumn), duration (minimum annual streamflow), timing (more floods in spring), and frequency (fewer prolonged floods). The land cover change (LCC) analysis indicated that more than 90% of the basin area maintained its land cover, and that the main changes were attributed to recent large wildfires. Considering these land cover trends, the hydrological simulations project a slight increase in the Puelo River streamflow mainly due to a decrease in evapotranspiration. According to previous simulations, these projections present a direction opposite to the trends forced by climate change. The combined effect of reduction in freshwater input to fiords and potential decline in water quality highlights the need for more robust data and robust analysis of the influence of climate and LCC on this river-fjord complex of northwestern Patagonia

A Genome-Wide Association Study for Agronomic Traits in Soybean Using SNP Markers and SNP-Based Haplotype Analysis - Fig 4

<p>Manhattan plot of GWAS for plant height (PH) evaluated in a soybean association mapping panel across the following environments of southern Brazil, A) Cascavel, B) Palotina, C) Primavera do Leste and D) Rio Verde. Negative log10-transformed P-values of SNPs from a genome-wide scan for PH using a mixed linear model that includes both kinship and populations structure are plotted against positions on each of the 20 chromosomes. The significant associations (P > 3.0 × 10⁻³) are distinguished by the threshold line.</p

Haplotypes associated with SW (mean in g/100 seed) in 169 cultivars of tropical soybean.

<p>Haplotypes associated with SW (mean in g/100 seed) in 169 cultivars of tropical soybean.</p

Genotypic correlations among seed yield (SY), seed weigh (SW) and plant height (PH) in tropical soybean by environment.

<p>Genotypic correlations among seed yield (SY), seed weigh (SW) and plant height (PH) in tropical soybean by environment.</p